Reference Design Episode Artwork for Bryden Wood's Built Environment Matters Podcast featuring Head of Global Systems, Jaimie Johnston MBE

In this special 'In Short' edition of Built Environment Matters, Head of Global Systems, Jaimie Johnston MBE gives us a sub-ten-minute lowdown on the essential elements of 'Reference Design.' Click the 'play button' to listen in, or read Jaimie's key takeaway article on the benefits of reference design below.

Defining reference design

What is a reference design and why use one?

Many major clients have national or global rollouts happening at a rapid pace. 

Often these clients are given a bespoke design to procure for every site, introducing unnecessary variation and complexity that adds cost and time to construction projects and ongoing operations.

Yet, from our experience, these clients have a very well-informed view on how their asset needs to perform and the layouts and designs that deliver their operational outcomes. This knowledge and understanding lends itself to a repeatable solution that can comprise c.80% of the asset. 

We call this a ‘Reference design’: a highly optimised, site agnostic ‘core design’ for a portfolio client, that can be adapted with a ‘local design’ adapted to specific sites. In reference design, we create a core design of the most common e.g. ‘mid-sized’ facility type, with a planned strategy for increasing or decreasing scale and content and ‘flexing’ to suit local conditions, considering and building in the ability to: 

  • scale up or down to hit a particular brief

  • rearrange or reconfigure to suit site constraints and layout

  • choose between a ‘seismic’ or ‘non-seismic’ version

  • choose between key suppliers for major equipment or specific materials required by fire codes etc.

Typically, a reference design will contain a number of repeated elements at varying scales (from key equipment to whole assets) that can be configured in a number of different ways (with more or less flexibility in how these are arranged depending on the asset type). 

We call these elements ‘Chips’ (read more about our Chip Thinking methodology here)

Figure 1 Chip hierarchies – healthcare example 

How are reference designs being used?

The house blocks we developed for the Ministry of Justice prisons rollout are a good example; highly standardised, they are identical on every site, but the number and orientation is dictated by the prison population and aspect/prospect of the site. The UK prisons rollout is reporting dramatic reductions in delivery schedule with much improved certainty on just the second project to use this approach. 

For a healthcare facility, the Chips may need to be much more flexible to accommodate specific clinical specialisms and the demographics of a particular region. 

Reference Design Example Configurations of Healthcare Chips

Figure 2 Example configurations of healthcare Chips

The ‘local’ design is then focused on ground conditions, utilities, infrastructure, placemaking, flows of people etc.

We introduced this concept to the New Hospitals Programme, developing the initial ‘Hospital 2.0’ solution. While this has since evolved, the use of reference designs continues to be a central part of their strategy to deliver schemes across the UK.

In addition to the public sector health and custodial programmers, we are currently deploying reference design across the private sector, particularly in the data centre market and for logistics and fulfilment centres.

The benefits of using a reference design even with a traditional supply chain

Sometimes the lack of supply chain maturity necessitates a more traditional construction process. However, even using a completely traditional build, reference design has numerous benefits:

  • It facilitates the introduction of industrialised construction (including platform approaches or P-DfMA) and the use of manufactured elements in construction

  • Often owned by the client, it gives greater control over IP and incorporates lessons learned to improve across design cycles

  • Multiple use allows for more design refinement, amplifying the benefit of good design 

  • It justifies a greater level of stakeholder engagement ensuring that designs are highly optimised in terms of layouts, space allocation, adjacencies, and functional flows

  • Designers can focus more of their efforts on solving the site and context specific challenges 

  • It facilitates efficient operation and maintenance

Critically, reference design gives teams the ability to assess a site very quickly using a ‘test fit’ process:

  • The client brief drives the selection of the appropriate Chips required to build the asset

  • These can then be arranged on the site according to the engineers’ predefined rules e.g. proximity of the Chips to one another; which ones can/can’t be stacked, which ones have to be next to each other vs separated etc.

  • This allows an initial solution (or multiple solutions) to be developed, with pre defined rules assuring compliance

  • These design solutions can be assessed and compared for optimisation of flows, simplicity of enabling works (cut and fill, extent of utilities works) etc.

  • This is not a complete design solution but can quickly generate a working feasibility model so clients can make highly informed decisions in days or weeks and at a fraction of the cost of a non ‘reference design’ approach

  • The design and procurement stages that follow can then also be compressed through focusing time and effort only on the bespoke elements.

This approach has been enormously powerful for our clients: the ability to rapidly assess the viability of sites has saved months of uncertainty and prevented the inefficiency of wasted work.